class Solution {
public:
    vector<int> searchRange(vector<int>& nums, int target) 
    {
        //边界情况处理
        if(nums.size() == 0)
            return {-1, -1};
        int begin = 0;
        //查找左端点
        int left = 0, right = nums.size() - 1;
        while(left < right)
        {
            int mid = left + (right - left) / 2;
            if(nums[mid] < target)
                left = mid + 1;
            else
                right = mid;
        }
        if(nums[left] != target)
            return {-1, -1};
        else
            begin = left;
        
        //left其实就是左端点，可以不用再置零
        right = nums.size() - 1;
        while(left < right)
        {
            int mid = left + (right - left + 1) / 2;
            if(nums[mid] > target)
                right = mid - 1;
            else
                left = mid;
        }

        return {begin, right};
    }
};